News / Science & Technology

Astronomers Say Galaxy May Be Awash with Homeless Planets

Artist's concept showing a free-floating planet with roughly the mass of Jupiter. These lone worlds, perhaps ejected from the planetary systems of their birth, are probably more common in our galaxy than stars.
Artist's concept showing a free-floating planet with roughly the mass of Jupiter. These lone worlds, perhaps ejected from the planetary systems of their birth, are probably more common in our galaxy than stars.

Astronomers say the Milky Way may be swarming with nomad planets wandering through space instead of orbiting a host star, and that the galaxy may have a greater number of unmoored planets than stars.

Last year, astronomers detected about a dozen nomad planets wandering about the galaxy, using a technique called gravitational microlensing, in which the light of stars is momentarily refocused, and brightened, by the gravity of passing planets.

At that time, scientists estimated there could be two Jupiter-sized nomad planets for every typical star with orbiting planets in the Milky Way.  Jupiter, a gas giant, is the largest planet in the solar system.

A new analysis by researchers at the Kavli Institute for Particle Astrophysics and Cosmology at Stanford University in California now estimates there could be 100,000 times more homeless planets than stars.

Louis Strigari, a research scientist at Kavli, led the study that calculated the gravitational pull of the Milky Way galaxy and the amount of cosmic matter, or material, available to form nomad planets.

"We imagined that the population of a dozen or so Jupiter-mass wandering or nomadic objects is just the tip of the iceberg relative to what’s really out there in terms of our galaxy," said Strigari.  "So, if one makes assumptions about how many there are below the mass below Jupiter, then one can obtain a bound [an estimate] on how many of these actually exist.

While they might seem to be unlikely candidates for life as we know it, StrIgari says it is possible some of these wandering planets could harbor forms of bacterial life, even if they do not enjoy the heat of a sun.

“If the object has a thick enough atmosphere and say there’s tectonic activity or radioactivity going on, on the surface of the planet, the heat could get trapped by the thick atmosphere and could potentially be hospitable to microbial life,” said the research scientist.

Strigari also says there is a slight chance that two nomad planets could collide, flinging bacterial debris into other solar systems.

Astronomers hope to confirm the number of wandering planets in the next decade, when a newer generation of larger, more powerful telescopes - including the space-based Wide-Field Infrared Survey Telescope and the ground-based Large Synoptic Survey Telescope proposed by the U.S. space agency (NASA) - begins operating.

An article by Louis Strigari and colleagues on nomadic planets is published in the journal Monthly Notices of the Royal Astronomical Society.

You May Like

Uganda Court Annuls Anti-Gay Law

Court says law was passed in parliament without enough members present for a full quorum More

Multimedia Thailand Makes Efforts to Improve Conditions for Migrant Laborers

In Thailand, its not uncommon for parents to bring their children to work; one company, in-collaboration with other organizations, address safety concerns More

In Indonesia, Jihad Video Raises Concern

Video calls on Indonesians to join Islamic State of Iraq and the Levant, ISIL More

This forum has been closed.
Comments
     
There are no comments in this forum. Be first and add one

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
In Thailand, Some Efforts to Improve Conditions For Migrant Laborersi
X
Steve Herman
August 01, 2014 6:22 PM
Thailand has been facing increasing international scrutiny as a hub of human trafficking and slave labor. Some of the kingdom’s companies are striving to improve working conditions, especially for the millions of migrant laborers from surrounding countries. VOA Correspondent Steve Herman in Bangkok takes a look at one initiative for children at construction sites
Video

Video In Thailand, Some Efforts to Improve Conditions For Migrant Laborers

Thailand has been facing increasing international scrutiny as a hub of human trafficking and slave labor. Some of the kingdom’s companies are striving to improve working conditions, especially for the millions of migrant laborers from surrounding countries. VOA Correspondent Steve Herman in Bangkok takes a look at one initiative for children at construction sites
Video

Video Public Raises its Voice on Power Plant Pollution

In the United States, proposed rules to cut pollution from the nation’s 600 coal-fired power plants are generating a heated debate. The U.S. Environmental Protection Agency, charged with writing and implementing the plan, has already received 300,000 written comments. As VOA’s Rosanne Skirble reports, another 1,600 people are lining up this week at EPA headquarters and at satellite offices around the country to give their testimony in person.
Video

Video Information War Rages Alongside Real One in Ukraine

The downing of the Malaysian airliner two weeks ago, and allegations that Russians are shelling Ukrainian troops across the border, have moved the information war swirling around the Ukrainian conflict to a new level. VOA's Al Pessin reports from Kyiv.
Video

Video When Fighting Eases, Gazans Line Up at Bakeries

When there is a lull in the conflict in Gaza, residents who have been hunkered down in their apartments rush out to stock up on food and other necessities. Probably the most important destination is the local bakery. VOA’s Scott Bobb reports from Gaza City.
Video

Video China Investigates Powerful Former Security Chief

The public in China is welcoming the Communist Party's decision to investigate one of the country's once most powerful politicians, former domestic security chief Zhou Yongkang. Analysts say the move by President Xi Jinping is not only an effort to win more support for the party, but an essential step to furthering much needed economic reforms and removing those who would stand in the way of change. VOA's Bill Ide has more from Beijing.
Video

Video US-Funded Program Offers Honduran Children Alternative to Illegal Immigration

President Obama and Central American leaders recently agreed to come up with a plan to address poverty and crime in the region that is fueling the surge of young migrants trying to illegally enter the United States. VOA’s Brian Padden looks at one such program in Honduras - funded in part by the United States - which gives street kids not only food and safety but a chance for a better life without, crossing the border.
Video

Video 'Fab Lab' Igniting Revolution in Kenya

The University of Nairobi’s Science and Technology Park is banking on 3-D prototyping to spark a manufacturing revolution in the country. Lenny Ruvaga has more for from Nairobi's so-called “FabLab” for VOA.
Video

Video Immigrant Influx on Texas Border Heats Up Political Debate

Immigrants from Central America continue to cross the U.S.-Mexico border in south Texas, seeking asylum in the United States, as officials grapple with ways to deal with the problem and provide shelter for thousands of minors among the illegal border crossers. As VOA's Greg Flakus reports from Houston, the issue is complicated by internal U.S. politics and U.S. relations with the troubled nations that immigrants are fleeing.

AppleAndroid